1: 54 percent / pyrrolidine / hexamethylphosphoric acid triamide / Ambient temperature 2: 97 percent / PPTS / CH2Cl2 / Ambient temperature 3: 98 percent / 0.13N LiOH / methanol; H2O / 18 h / 50 °C 4: 93 percent / n-Bu4NF / tetrahydrofuran / 5 h / Ambient temperature 5: 47 percent / triphenylphosphine, dipyridyl disulfide / xylene / Ambient temperature 6: 35 mg / acetic acid; tetrahydrofuran; H2O / 4 h / 50 °C 7: TiCl4 / CH2Cl2 / 0.25 h / 0 °C View Scheme